JPH08135377A - Tunnel excavator - Google Patents

Abstract

PURPOSE: To carry out the excavation smoothly, by simplifying the structure of a tunnel excavator with an elliptical cross section, and reducing the friction force generated between a holding member which receives an excavation reaction in the tunnel peripheral direction, and a pit wall. CONSTITUTION: At the front part of a main frame 1, a cutter head 3 is held by inclining a specific angle to the vertical surface. And, to the main frame 1, a roof support 5 is provided at the position corresponding to the excavation reaction in the tunnel peripheral direction generated by the rotation of the cutter head 3. Furthermore, a pressing device 21 to press the roof support 5 to the cutter head 3 side against the excavation reaction is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel excavator, and more particularly to a tunnel excavator for excavating a tunnel having an elliptical cross section.

[0002]

2. Description of the Related Art Conventionally, a tunnel excavator for excavating rock has a structure in which a cylindrical cutter head is arranged at the front of the excavator body and a circular cutter surface is provided in front of the excavating direction of the cutter head. Are known. In this tunnel excavator, a pair of gripper devices are provided so as to be slidable in the front-rear direction with respect to the excavator body, and these gripper devices and the excavator body are connected by a thrust cylinder. The excavator body is advanced by extending the thrust cylinder while rotating the cutter head in a state of pressing the wall against the wall, releasing the pressing of the gripper device after advancing at a predetermined pitch, and contracting the thrust cylinder to excavate the gripper device. It is designed to move forward with respect to the main body to continuously excavate. Such a tunnel excavator is usually used when excavating a tunnel having a circular excavation cross section, such as a water channel or water and sewer.

However, when excavating a tunnel used for a double-track railroad or a road, etc., if a tunnel having a circular cross section is excavated by using the tunnel excavator as described above, the required space is rectangular. Therefore, there is a problem that the amount of excess excavation increases and extra cost is required for backfilling after excavation, which is inefficient and uneconomical.

Therefore, in order to reduce the amount of excess excavation, a tunnel excavator (tunnel boring machine) capable of excavating a tunnel having an elliptical cross section has been proposed, for example, in Japanese Patent Laid-Open No. 4-353192. In the tunnel excavator disclosed in this publication, a cutter head having a circular cutter surface can be tilted at an arbitrary angle with respect to the apparatus body by expansion and contraction of a cylinder member,
As a result, a desired elliptical tunnel can be excavated.

Further, in Japanese Patent Application No. 4-3202071, in a tunnel excavator in which a cutter head can be tilted at an arbitrary angle with respect to an apparatus main body, an excavation reversal in a tunnel circumferential direction caused by the tilt of the cutter head. There has been proposed a tunnel excavator equipped with a pressing device that presses a pressing force that opposes a force toward the cutter head by using a pit wall as a reaction force.

[0006]

However, in the previously proposed elliptic section tunnel excavator described above, since the cutter head can be adjusted to an arbitrary angle, it is necessary to change the angle of the cutter head, for example. A mechanism such as a cylinder member is required. When excavating, the total excavation reaction force is applied to the mechanism such as the cylinder member,
There is a problem that a considerably large cylinder member must be prepared, and the control mechanism of the cylinder member becomes large and complicated in order to keep the inclination angle of the cutter head constant during excavation. There is a problem.

Further, in the previously proposed elliptical tunnel excavator, the roof support (support member) which receives an excavation reaction force in the tunnel circumferential direction caused by the inclination of the cutter head moves integrally with the excavator body. Therefore, when excavating the excavator main body, an extremely large frictional force is generated between the roof support and the pit wall, and this frictional force becomes a resistance when the excavator main body is excavating, and the excavation cannot be performed smoothly. There is a problem.

The present invention has been made in order to solve such problems, and, firstly, an object thereof is to simplify the structure of an elliptic tunnel excavator. Secondly, the present invention reduces the frictional force generated between the support member that receives an excavation reaction force in the tunnel circumferential direction and the pit wall in the elliptical tunnel excavator so that the excavation can be performed smoothly. The purpose is to do.

[0009]

The tunnel excavator according to the present invention is a tunnel excavator for excavating a tunnel having an elliptical cross section, in order to achieve the first object, and An excavator main body, (b) a cutter head having a circular cutter surface on a front surface in the excavation direction, which is supported at a front portion of the excavator main body at a predetermined angle with respect to a vertical plane.
(C) A supporting member provided at a position corresponding to the excavation reaction force in the tunnel circumferential direction generated by the rotation of the cutter head, and (d) the support member is pressed against the excavation reaction force toward the cutter head side. It is characterized by comprising a pressing means.

In the invention having such characteristics,
When the cutter head is rotated to advance the excavator body,
A tunnel having an elliptical cross section is excavated by supporting the cutter head at a predetermined angle with respect to the vertical plane. At the time of this excavation, the excavation reaction force in the tunnel circumferential direction caused by the inclination angle of the cutter head is received by the support member, and the excavation reaction force applied to the support member is pressed to the cutter head side by the pressing means. As a result, the tunnel wall is canceled as a reaction force,
As a result, the desired excavation is performed in the direction of excavation.

In the present invention, since the inclination angle of the cutter head with respect to the excavator body is fixed, the structure can be extremely simplified as compared with an excavator of a type in which the inclination angle of the cutter head can be arbitrarily changed. In addition to being able to do so, it is possible to always excavate a constant elliptical section tunnel stably.

In the present invention, it is preferable to further include control means for controlling the pressing means so that the support member is always held at a fixed position with respect to the excavator body.
By such control means, the support member is always held at a fixed position, and the straightness of the excavator body is maintained.

In the present invention, in order to further achieve the second object, the support member and the pressing means are held at predetermined positions when the excavator main body is excavated, and the excavator main body is excavated at a predetermined pitch. It is preferable to provide position adjusting means for moving the supporting member and the pressing means to the position before the excavation later. With such a position adjusting means, the excavator main body is advanced while the support member is pressed against the natural ground by the pressing means when the excavator main body moves forward (during excavation). At this time, since the excavator main body and the pressing means are slidable, only the excavator main body moves forward and the supporting member receives the reaction force from the pit wall and holds the stationary position with respect to the pit wall. At the same time, the position adjusting means is contracted. After that, when the excavator main body is advanced by a predetermined pitch, the pressing means is contracted to separate the support member from the ground, and in this state, the position adjusting means is extended to advance the support member and the pressing means to move these support members. And the pressing means is returned to the initial position with respect to the excavator body. Thus, the frictional force generated between the support member and the pit wall during the excavation of the excavator main body is replaced by the smaller frictional force between the pressing means and the excavator main body, thereby reducing the resistance force during the excavation. As a result, the digging operation is performed more smoothly.

The pressing means comprises a hydraulic cylinder arranged between the excavator body and the support member, and the control means controls the stroke of the hydraulic cylinder so as to always match the reference stroke. Can be.

The angle of inclination of the cutter head with respect to the vertical plane is preferably in the range of 32 ° to 45 °. In this way, the inclination angle in the range of 32 ° to 45 ° is selected, for example, to minimize the amount of excess excavation when excavating a two-lane tunnel or a railway double-track tunnel, shorten the construction period, and improve work efficiency. This is for improvement. Inclination angle θ
Considering the force acting on the cutter head having
As shown in FIG. 11, when excavating force is applied to the inclined cutter, the cutter load P _d becomes a load P _d c in the propulsion direction.
and Osshita, is a component force in a load P _d sin [theta of vertically downward, each of these component forces P _d cos [theta], the cutter head is the force P _d cos [theta] and the propulsion direction and opposite from the natural ground so as to correspond to the P _d sin [theta It will receive a force P _d sin θ in the vertically upward direction. Therefore, when the inclination angle θ of the cutter head becomes larger than 45 °, P _d cos θ <P _d sin θ
In other words, the lifting force of the excavator body becomes larger than the propulsion force, and the loss of the propulsion force becomes extremely large. As a result, a large force is required for the support member to suppress the lifting force of the excavator body. For this reason, the upper limit of the inclination angle θ of the cutter head is set to 45 °. The value of the inclination angle of 32 ° is selected as a value that can obtain the excavation cross-sectional area equivalent to that of the inclination angle of 45 °.

Further, in the present invention, it is preferable that the outermost cutter of the cutter head is attached to the cutter head face plate so as to be inclined backward by a predetermined angle. By doing this, the outermost peripheral surface of the tunnel is excavated by the cutter, even though the cutter head is attached to the excavator main body in an inclined manner, so that the excavation outer diameter is sufficiently secured and the desired Excavation work can be performed.

Objects of the present invention will become apparent from the detailed description given below. However, while the detailed description and specific examples describe the most preferred embodiments, various modifications and variations within the spirit and scope of the invention will be apparent to those skilled in the art from the detailed description, and therefore, specific examples As described below.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of the tunnel excavator according to the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a tunnel excavator according to an embodiment of the present invention, FIG. 2 is a view taken along arrow A of FIG. 1, FIG. 3 is a view taken along arrow B of FIG. 1, and FIG. A sectional view taken along the line CC of FIG. 1 is shown in FIG.
1 is a sectional view taken along the line DD of FIG.

In the tunnel excavator of this embodiment, a main frame 1 extending in the front-rear direction is provided, and a cutter head 3 is provided at a front portion of the main frame 1 via a bearing 2 with respect to a vertical plane. It is rotatably supported in a tilted state. Here, this cutter head 3
The angle of inclination with respect to the vertical plane is 32 °, as described later.
An angle in the range of 45 ° is preferred. The cutter head 3 is supported by a cutter head support 4 attached to the front portion of the main frame 1, and a roof support 5 (described in detail later) is provided on the upper portion of the main frame 1. In this way, the tunnel excavator is supported by the cutter head support 4 and the roof support 5 in the vertical direction for excavation.

The cutter head 3 has a circular cutter surface on the front surface. In addition, the front plate 6 of the cutter head 3
In the center, a plurality of excavation cutters 7 are rotatably supported in a central portion and a peripheral portion thereof, and a plurality of earth and sand intake scrapers 8 are provided in the vicinity of a peripheral edge portion thereof, and further, these scrapers 8 are taken in by A scraping plate 9 for scraping up the earth and sand is provided.

The cutter head 3 is driven by a plurality (six in this embodiment) of drive motors 11 attached to the cutter head support 4. here,
As shown in FIGS. 3 and 4, these drive motors 11 are attached to the lower half portion of the cutter head 3 so as to gather. By doing this, these drive motors 1
It is possible to avoid the interference between 1 and other mechanisms, and to effectively use the space inside the machine.

Further, a hopper chute 12 for receiving earth and sand taken into the cutter head 3 is provided at a substantially central portion of the cutter head 3, and the hopper chute 12 is provided.
A base end portion of a belt conveyor 13 that carries out the earth and sand received by the hopper chute 12 rearward is disposed below the. The belt conveyor 13 extends along the main frame 1 to the rear of the main frame 1. In this way, when the cutter head 3 is rotated, the ground is excavated by the excavation cutter 7, and the excavated earth and sand is scraped up by the scraping plate 9 and carried out rearward via the hopper chute 12 and the belt conveyor 13.

A pair of left and right gripper devices 14 are arranged on both sides of the main frame 1 so as to be slidable in the front-rear direction with respect to the main frame 1. The front part of the gripper device 14 and the front part of the main frame 1 are connected by a plurality of thrust cylinders 15, and the main frame 1 can be dug by the operation of these thrust cylinders 15. A rear support 16 that supports the main frame 1 from below by a cylinder mechanism is provided at the rear end of the main frame 1. These rear supports 16 serve to support the main frame 1 when the gripper device 14 releases the main frame 1 from being fixed to the pit wall.

As shown in FIG. 5, the gripper device 14 has a gripper shoe 17 formed to have substantially the same curvature as the inner peripheral surface of the already excavated pit wall, and the gripper shoe 17.
And a gripper cylinder 18 for moving the above to be pressed against the wall surface of the mine. In this way, the left and right gripper shoes 17 are pressed against the pit wall surface by the operation of the gripper cylinder 18, so that the main frame 1 is supported in the tunnel. Reference numeral 19 in FIG. 1 indicates an advanced boring for boring the ground prior to the excavation of the excavator, and reference numeral 20 in FIGS. 1 and 5 indicates a pit wall reinforcement after excavation. Is a rock drill for drilling a steel material insertion hole for.

The gripper device 14 and the rear support 16
And the excavation operation using the thrust cylinder 15 is performed as follows.

First, the gripper cylinder 18 of the gripper device 14 is operated in the extension direction to press the gripper shoe 17 against the pit wall to fix the main frame 1 to the ground, and in this state the cutter head 3 is rotated and the thrust cylinder is rotated. 15 is operated in the extension direction, and the gripper device 1
4, the main frame 1 is moved forward while the excavation reaction force is obtained to excavate the ground. At this time, the rear support 16
Is in a contracted state.

Next, when the thrust cylinder 15 extends to the stroke end and the excavation for a predetermined pitch is completed and the main frame 1 is temporarily stopped, the rear support 16 is actuated in the extension direction to move the main frame 1 to the pit wall. The main frame 1 is pressed and fixed to the ground, while the gripper cylinder 18 of the gripper device 14 is operated in the contracting direction to separate the gripper shoe 17 from the pit wall. In this state, the thrust cylinder 15 is operated in the contracting direction to pull the gripper device 14 forward to the initial position. The excavation is advanced by sequentially repeating such operations.

Next, the specific structure of the roof support 5 will be described. The roof support 5 is formed in an arcuate cross section so as to abut against the pit wall, and as shown in FIG. 6, at the upper position on the back side of the cutter surface of the cutter head 3,
In other words, it is provided at a position corresponding to the excavation reaction force in the tunnel circumferential direction caused by the inclination of the cutter head 3. The roof support 5 is attached to an upper part of a pressing device 21 provided on the main frame 1 so as to be slidable in the front-rear direction, and is operated integrally with the pressing device 21 by operating a slide cylinder 22 attached to the main frame 1. Be slid on. Here, the pressing device 21 includes a plurality of roof support cylinders 23, and the tips of the rods of the roof support cylinders 23 are connected to the lower surface of the roof support 5.

The roof support 5 configured as described above operates as follows when the excavator body is excavated. When the main frame 1 is advanced (during excavation), the roof support cylinder 23 first presses the roof support 5 against the ground, and then the thrust cylinder 15 is extended to advance the main frame 1. At this time, since the main frame 1 and the pressing device 21 are slidable, only the main body of the excavator moves forward and the roof support 5 receives a reaction force from the pit wall and is in a stationary position with respect to the pit wall. The slide cylinder 22 is contracted at the same time. After that, when the excavator body advances by a predetermined pitch, the roof support cylinder 23 is contracted to separate the roof support 5 from the ground, and in this state, the slide cylinder 22 is extended to advance the roof support 5 and the pressing device 21. Then, the roof support 5 and the pressing device 21 are returned to the initial position with respect to the main frame 1. Thus, the roof support 5 during the excavation of the excavator body
The frictional force generated between the shaft and the pit wall can be replaced with a smaller frictional force between the pressing device 21 and the main frame 1, thereby reducing the resistance force during the digging and making the digging operation smoother. It becomes possible to do.

Further, in the tunnel excavator of this embodiment, since the cutter head 3 is inclined, when a propulsive force is applied to the cutter head 3 from the rear, the face of the excavator is passed from the face through the cutter head 3. Upward excavation reaction force Fsin
θ (F: cutter load, θ: cutter head inclination angle) is applied, and the roof support 5 is about to be lifted by this excavation reaction force. In this case, the oil in the roof support cylinder 23 is slightly compressible, and since the oil slightly leaks, the roof support cylinder 2
The stroke 3 changes. When the stroke of the roof support cylinder 23 changes in this way, the straightness of the excavator cannot be maintained. Therefore, in this embodiment, the stroke control of the roof support cylinder 23 is performed so that the stroke is always constant. .

Next, the roof support cylinder 23
The stroke control of No. 1 will be described with reference to the flowchart shown in FIG.

S1 to S3: When the tunnel excavator is not in the excavating operation and the roof support cylinder 23 is not extended to the reference stroke, the roof support cylinder 23 is extended to the reference stroke. On the other hand, when the excavation operation is in progress, the process proceeds to step S5 described later. When the roof support cylinder 23 is not in the excavation operation and extends to the reference stroke, step S3 is skipped and the process proceeds to step S4. The reference stroke is the stroke of the roof support cylinder 23 when the roof support shoe contacts the pit wall by design and is stored in the storage device in advance.

S4: It is determined whether or not the excavation operation of the tunnel excavator is started. If it is started, the process proceeds to step S5, and if not started, the flow is ended.

S5 to S7: When the excavation operation is being performed, the difference between the current stroke of the roof support cylinder 23 and the reference stroke is calculated, and if this difference is within a predetermined allowable value ± a, step Proceed to S8. On the other hand, when the difference is smaller than −a, the roof support cylinder 23 is extended and the process returns to step S5. When the difference is greater than + a, the roof support cylinder 23 is contracted and the process returns to step S5. The control of the roof support cylinder 23 is performed by controlling the hydraulic pressure supplied to the roof support cylinder 23 by a cylinder controller (not shown).

S8-S9: Continue the excavation, then determine whether or not the excavation has stopped. If the excavation has stopped, the flow is ended. If not stopped, the process returns to step S5 to perform stroke control. continue.

[0037] Thus, the roof support 5 is always controlled so as to maintain a constant position, whereby the drilling reaction force Fsinθ exerted upwardly on the excavator main body are canceled by the reaction force (pressing force) F _R from pit wall, The excavator body goes straight in the desired direction of excavation.

In the present embodiment, the inclination angle θ of the cutter head 3 with respect to the vertical plane is preferably in the range of 32 ° to 45 ° as described above. 32 ° -4 in this way
The inclination angle in the range of 5 ° is selected in order to minimize the amount of excess excavation when excavating a two-lane tunnel or a railway double-track tunnel, shorten the construction period, and improve work efficiency. .

As an example, FIG. 8 shows the relationship between the cutter head inclination angle θ and the minimum sectional area M at each cutter head outer diameter φ (= the length of the major axis) for a standard section of a railway double-track tunnel. . In addition, in the data shown in FIG. 8, the sectional shapes at θ = 0 °, 39.5 °, and 45 ° are shown in FIG.
(A)-(c) respectively. Further, FIG. 10 shows the same relationship as in FIG. 8 for the standard cross section of the two-lane road tunnel. These FIG. 8, FIG. 9 and FIG.
As is clear from the above, in both cases of the railway double-track tunnel and the two-lane road tunnel, the excavation cross-sectional area becomes the minimum when the cutter head inclination angle θ is around 40 °.
It can be seen that the excavation cross-sectional area increases evenly around 0 °. When the inclination angle θ exceeds 45 °, the lifting force against the thrust of the excavator body becomes large, the excavation efficiency becomes poor, and the roof support 5 becomes large and acts on the bearing in the excavation cutter 7. The thrust force to be increased also requires a large capacity bearing, and the excavation cutter 7 becomes large. Further, it becomes difficult to secure a space for installing the drive motor 11, the belt conveyor 13, the main frame 1 and the like, and a work space for maintenance and inspection and repair of the cutter head 3 and the like cannot be secured. The value of the inclination angle of 32 ° is selected as a value that can obtain the excavation cross-sectional area equivalent to that of the inclination angle of 45 °.

Further, in this embodiment, as shown in FIG. 6, the excavation cutter 7 attached to the outermost periphery of the cutter head 3 can secure the excavation outer diameter with respect to the front plate 6 of the cutter head 3. It is arranged to be tilted backward by a predetermined angle within the range. By doing so, it is possible to prevent the uncut portion from occurring in the vicinity of the outer peripheral portion of the cutter head 3, and it is possible to secure a sufficient excavation outer diameter.

In the present embodiment, the automatic stroke control of the roof support cylinder 21 has been described, but a stroke meter for instructing the stroke of the roof support cylinder 21 is provided at an appropriate position of the pressing device 19, and the stroke of this stroke meter is adjusted. The operator may manually operate the hydraulic valve of the roof support cylinder 21 while watching the instruction value at the driver's seat.

As described above, it is obvious that the present invention can be modified in various ways. Such modifications are within the spirit and scope of the invention, and all such variations and modifications apparent to those skilled in the art are intended to be within the scope of the following claims.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a tunnel excavator according to an embodiment of the present invention.

FIG. 2 is a view on arrow A of FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a cross-sectional view taken along the line CC of FIG.

5 is a cross-sectional view taken along the line DD of FIG.

FIG. 6 is an enlarged cross-sectional view of a main part of FIG.

FIG. 7 is a flowchart of stroke control of a roof support cylinder.

FIG. 8 is a graph showing the relationship between the cutter head inclination angle and the minimum sectional area for a standard section of a railway double-track tunnel.

9 is a diagram showing an excavation cross-sectional shape corresponding to a specific cutter head inclination angle in the data shown in FIG. 8;

FIG. 10 is a graph showing the relationship between the cutter head inclination angle and the minimum sectional area for a standard section of a two-lane road tunnel.

FIG. 11 is a diagram illustrating the relationship between the lifting angle of the excavator body and the inclination angle of the cutter head.

[Explanation of symbols]

 1 Main Frame 3 Cutter Head 5 Roof Support 6 Front Plate 7 Excavation Cutter 11 Drive Motor 21 Pressing Device 22 Slide Cylinder 23 Roof Support Cylinder

 ─────────────────────────────────────────────────── ─── Continued Front Page (71) Applicant 000201478 Maeda Construction Co., Ltd. 2-1026 Fujimi, 2-chome, Chiyoda-ku, Tokyo (72) Inventor Takashi Sakai 2-10-2 Otowa NS Bunkyo-ku, Tokyo Otowa NS Building 7th floor, Foundation for Advanced Construction Technology (72) Inventor, Shota Takatsu, 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Incorporated in the company group (72) Inventor, Yoshiaki Ishida 4-12-20 Nihonbashi-honcho, Chuo-ku, Tokyo Sato Industry Co., Ltd. (72) Inventor, Yoshito Minami 3-1-1, Ueno, Hirakata-shi, Osaka Komatsu Ltd., Osaka Plant (72) Inventor, Tomio Hibiya, Fujimi 2-1026, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (6)

[Claims] 1. A tunnel excavator for excavating a tunnel having an elliptical cross section, comprising: (a) an excavator body, and (b) a front portion of the excavator body, which is supported at a predetermined angle with respect to a vertical plane. A cutter head having a circular cutter surface on the front surface in the direction of excavation, (c) a support member provided at a position corresponding to an excavation reaction force in the tunnel circumferential direction generated by the rotation of the cutter head, and (d) the excavation of the support member. A tunnel excavator, comprising a pressing means for pressing against the cutter head side against a reaction force. 2. The tunnel excavator according to claim 1, further comprising control means for controlling the pressing means so that the support member is always held at a fixed position with respect to the excavator body. . 3. The supporting member and the pressing means are held at predetermined positions during the excavation of the excavator body, and the supporting members and the pressing means are moved to the position before excavation after excavating the excavator body at a predetermined pitch. The tunnel excavator according to claim 1 or 2, further comprising: a position adjusting unit that moves the tunnel. 4. The cylinder, wherein the pressing means comprises a hydraulic cylinder arranged between the excavator body and the support member, and the control means controls so that the stroke of the hydraulic cylinder always matches a reference stroke. The tunnel excavator according to claim 2 or 3, which is a controller. 5. The angle of inclination of the cutter head is 32 ° to
The tunnel excavator according to any one of claims 1 to 4, wherein the angle is in the range of 45 °. 6. The tunnel excavator according to claim 1, wherein the cutter on the outermost periphery of the cutter head is attached to the cutter head face plate so as to be inclined rearward at a predetermined angle. .